1. Field of the Invention
This invention is directed to roller apparatus. More specifically, this invention is directed to roller apparatus which utilize a core roll and a removeable blanket mounted thereon. Typical applications for such roller apparatus include tensioning rollers as are utilized in the textile industry, backing rollers such as are utilized in the printing industry and anvil type rollers which are utilized in the die cutting industry. These, of course, are only typical applications and many other such applications will be immediately recognized by those having skills in these arts.
2. Description of the Prior Art
It has been long recognized in the machine design industry that a roller apparatus including a basic structural core and a replaceable blanket cover are highly desirable because of the economics involved. Clearly it is more desirable to replace a cover on a roll type device rather than to replace the entire device. This recognition has been reflected in the state of the art and such replaceable blankets are disclosed in U.S. Pat. Nos. 4,073,208 and 4,073,207 as well as in the patent cited in their prosecution.
The split type blankets which have been developed for and utilized primarily in the die cutting industry are beneficial because they permit mounting of the blanket on a core without the necessity for disassembling the machine with respect to which the roller is being utilized.
As experience in the art has developed, however, certain problems have been identified. Among these is that many of the structures for locking the blankets in place on the cores are complex and expensive. Additionally, installation of the blankets often requires access to the entire transverse surface of the core which, in many applications, is not possible. Still further, the amount of time required to effect a blanket replacement, while improved over what was previously accepted in the prior art, still is subject to further improvement.
It should also be noted that in many fields, particularly the textile and related industries, general acceptance of replaceable blankets for rollers has not been achieved. One reason for this is the fact that many rollers in this industry are non-cylindrical in shape thus rendering the problem of locking the blanket with respect to the roller to be significant. Heretofore many such non-cylindrical rollers e.g., frustoconical rollers, have been traditionally structured, i.e., the cover material has been placed on the core by casting or vulcanizing and thereafter the surface machined to be true. This process, of course, is extremely expensive and the expense is compounded when the surface of the roller is subjected to wear such as to require replacement. In such circumstance the entire roller apparatus must be removed from the machine and replaced with a different roller. Thus the machine owner is required to maintain an inventory of fresh rollers so that the apparatus will not be inoperable during roller replacement. Further, actual removal of the rollers and installation of the new rollers requires down time sufficient to disassemble the structure and thereafter reassemble with the new roller in position. Clearly, the foregoing constitutes an uneconomical approach to the problem.